Hartov Alex, Roberts David W, Paulsen Keith D
Thayer School of Engineering, Dartmouth College, HB 8000, Hanover, NH 03755, USA.
Neurosurgery. 2008 Mar;62(3 Suppl 1):91-9; discussion 99-101. doi: 10.1227/01.neu.0000317377.15196.45.
This work presents qualitative and quantitative side-by-side comparisons of oblique coregistered magnetic resonance imaging (MRI) scans and ultrasound images obtained during 35 neurosurgical procedures.
Spatially registered series of ultrasound images were recorded for subsequent off-line evaluation and comparison with corresponding preoperative MRI studies. The degree of misalignment was reduced by reregistering the target volume directly with segmented features.
The initial apparent spatial misalignment of the target volume after craniotomy ranged from 0.11 to 8.73 mm (mean, 4.01 mm). After reregistration, the mutual information in overlapping segmented features was increased, presumably evidence of a better alignment locally. Additionally, the degree of feature congruence, which was assessed quantitatively through a convex hull approximation, demonstrated that the ultrasound volume was consistently smaller than its MRI counterpart.
Although intraoperative ultrasound tends to be difficult to interpret by itself, when accurately coregistered with preoperative MRI scans, its potential utility as a navigational guide is enhanced.
本研究对35例神经外科手术过程中获得的斜向配准磁共振成像（MRI）扫描图像和超声图像进行了定性和定量的并行比较。
记录空间配准的超声图像序列，以便后续进行离线评估，并与相应的术前MRI研究进行比较。通过直接使用分割特征重新配准目标体积，减少了错位程度。
开颅术后目标体积最初的明显空间错位范围为0.11至8.73毫米（平均4.01毫米）。重新配准后，重叠分割特征中的互信息增加，这可能是局部对齐更好的证据。此外，通过凸包近似法进行定量评估的特征一致性程度表明，超声体积始终小于其对应的MRI体积。
尽管术中超声本身往往难以解读，但与术前MRI扫描准确配准后，其作为导航指南的潜在效用会增强。
